Carbon for electric lights



(No Model.)

E. G. AGHESON. GARBON FOR ELECTRIC LIGHTS.

110,527,826 Patented Oct. 23, 1894.

Ma/M l V NITED STATES PATENT OFFICE. v

EDWARD GOODRICI-I AOHESON, OF MONONGAHELA CITY, PENNSYLVANIA.

CARBON FOR ELECTRIC LIGHTS.

SPECIFICATION forming part of Letters Patent No. 527,826, dated October23, 1894.

Application filed August'25, 1894. Serial No. 521,324. (No model.)

To all whom it may concern.-

Be it known that I, EDWARD GOODRICH AOHESON, acitizen of the UnitedStates, residing at Monongahela City, in the county of 5 Washington andState of Pennsylvania, have invented certain new and useful Improvementsin Oarbons for Electric Lamps, of which the following isa-specification.

My invention relates to carbons, and more especially to that class ofcarbons which are adapted for use in connection with the electriccurrent, such as the points or rods for are lighting, the filaments forincandescent lighting, and other forms, and it has for its object toproduce an improved illuminating body which may be so used, and whichshall have the properties among others, of prolonged life and greaterefficiency, producing a greater light value for the electric energyutilized, and to these ends my invention consists in a carbon orfilament composed essentially of carbon, having associated with it andforming a part thereof, a certain proportion of carbide of silicon.

It is well known that many eiforts have been made to improve the qualityof illuminating carbons, for the purpose of lengthening the life of thefilaments, rods or points, and also that many efforts have been made toproduce a combination of carbon with other substances for the purpose ofproducing more light for the electrical energy consumed, and for thispurpose many and various combinations of materials have been made, bothin the mass 3 5 of the filament, rod or point, or in the coating of themass. Without reciting all the efforts which have been made in thisdirection )with greater or less success, it has been one I of theprincipal objects of my present inven- 40 tion to produce anilluminating carbon conl taining a material having an excessively high ifusing point and equally difficult of oxida- With these generalstatements of the objects and purposes of my invention, I will nowproceed to describe the embodiment thereof and the manner in which myinvention is carried out, and it will be understood that while I havedescribed What may be considered as a preferable embodiment of myinvention, I do not limit myself to the precise conditions orproportions herein set forth, as they may be varied by those skilled inthe art in accordance with the particular purposes for which the carbonsare'intended, and the conditions under which they are'to be utilized.

In the accompanying drawings, I have shown several typical forms ofilluminating bodies or carbons embodying my invention, sufficient toenable those skilled in the art to understand the same, and in which-Figure 1, is a representation of an ordinary solid carbonrod. Fig. 2, isa representation of a cored carbon rod; and Fig. 3, is a representationof a filament of an incandescent lamp.

In carrying out my invention I take pre ferably pure carbon, andpreferably reduce it to a finely pulverized condition, and also takecarbide of silicon in a similar condition, and thoroughly mix the twotogether, and these may be united by any appropriate or well-knownbinding material, such for instance, as tar. While the proportions maybe varied considerably, according to the purposes for which the carbonsare intended, a mixture of ninety per cent. of carbon and ten per cent.of carbideof silicon, in the conditions above indicated, producesefficient and satisfactory results. When the carbons are to be used asrods, points, or other forms, in an electric arc, this mixture may betreated or manipulated in any of the well-known ways,

by compression, baking, coated, &c., which need not be fully set forth.

For some particular purposes, it has been found advisable to use a coredcarbon rod or point, the core being formed of substances other thancarbon, and where such form is desirable, as well as to get the full andcomplete elfect of the illuminating qualities of the carbide of siliconmore distinctly sepa rated from that of the carbon, the ordinary coredcarbon rod or point is used and the contral space is filled with thecarbide of silicon, either alone or with a suitable binding agent, asindicated in Fig. 2.

In the use of the carbide of silicon in connection with the carbon ofthe filaments for incandescent lighting, the carbide of silicon isintermingled with the portions of the carbon at the surface andextending inward for any desired depth, and it is intermingled and fixedin any suitable way, as for instance, the carbide of silicon in a veryfine powder or dust is mixed with and suspended in the oil used in thewell-known oil bath, for the treatment and building up of the carbons,and in the process of depositing the carbon from the oil bath onto thefilament, the fine particles of carbide of silicon, being about and incontact with the filament, become fixed to the filament simultaneouslywith the deposit of carbon and become a part of the filament, the amountof carbide of silicon fixed in the carbon being governed, among otherthings, by the amount suspended in the oil. Other ways of combining thecarbide of silicon with the filament, of course, may be utilized,according to the specific results intended to be produced.

Carbide of silicon is a product which was first produced by myself, andwhich has been formed at a temperature approximately that of theelectric arc,and which is, as a result, free from all volatile mattersand eminently fitted (as the result of having already existed at thesehigh temperatures) for the lightgiving body. It has also beendemonstrated that it resists oxidation to a greater extent than anyother known material, having resisted such chemical action when highlyheated and exposed to a stream of oxygengas. Associated with these twoessential qualifications of infusibility and non-oxidizability, is athird equally valuable one, of luminescence, it producing a greaternumber of light-waves for the electrical energy consumed than thoseilluminating bodies heretofore used.

While carbide of silicon has the essential characteristics of anilluminating body as above stated, it is in itself deficient in theelectrical conductivity necessary to rods or points of arc lights, andfor that reason it is associated with carbon in their formation.

What I claim is 1. An illuminating body for electric lamps, comprisingcarbon associated with carbide of silicon, substantially as described.

2. A carbon rod, point or filament for electric lamps, comprisingcarbide of silicon as an illuminating body, associated with a body ofrelatively high electrical conductivity, as carbon, substantially asdescribed.

3. A carbon rod or point for electric lamps, comprising an outer body ofcarbon and a core of carbide of-silicon, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

EDWARD GOODRICH ACIIESON.

Witnesses:

F. L. FREEMAN, A. N. DOBSON.

